Which of the following molecules would most likely cross a cell membrane by passive diffusion rather than facilitated diffusion or active transport?
Show answer and explanation
Correct answer: O₂ (oxygen) gas
Oxygen is a small nonpolar gas that can dissolve in the hydrophobic core of the membrane and cross by simple diffusion; charged ions and large polar molecules generally require transport proteins.
Keep practicing
More Membrane Transport Mechanisms questions
- What distinguishes primary active transport from secondary active transport (cotransport)?
- Which of the following best defines osmotic flow across a biological membrane?
- Which statement best explains why charged ions such as Na⁺ or K⁺ cannot cross the plasma membrane by simple diffusion under normal conditio…
- Which transport process would be used by a renal tubular cell to reabsorb glucose from the filtrate into the bloodstream against its concen…
- Which of the following mechanisms requires ATP directly for transport of ions across the plasma membrane?
- What does the term “carrier-mediated transport” typically refer to in cell physiology?